A computer system in which a touch-screen display displays an electronic program guide to a user. A first user can book to watch a television program at a future time by selecting a “book to watch” button 56 on the EPG. The first user can then invite a number of contacts to watch the television program as well. Invitations are sent to the contacts' devices using a server, and an indication of those contacts that have accepted the invitation is displayed on an EPG associated with the first user.